A bifunctional interlayer fabricated by FeS2-embedded N-doped carbon nanocages with efficient polysulfide trapping-catalyzing capability for robust Li-S batteries

N-doped Fe2(MoO4)3-decorated MoO3 nanorods via metal–organic framework-involved synthesis as a bifunctional nanoreactor for capturing and catalyzing polysulfides in lithium–sulfur batteries

“…This is related to a change in electron density due to the introduction of N and Fe elements. 14,20 These test results show that N-MoO 3 @Fe 2 (MoO 4 ) 3 was successfully synthesized.…”

“…They are usually characterized by highly conductive networks, high specific surface areas, and stable structure, widely being employed in LSB coating materials to anchor LiPSs. 13,14 However, limited by weak interactions between the polar and nonpolar LiPSs these carbon materials cannot absorb LiPSs continuously, resulting in a poor battery cycle performance. 15 Most importantly, the issue of slow dynamics is not addressed.…”

“…Introducing a functionalized interlayer in the form of a separator coating is one of the rational strategies to block polysulfide shuttling and enable their rapid transformation. 14,18 To be more specific, it is the cathode side that the diffusion of polysulfides originates from. Inserting a coating layer between the separator and the cathode can block the immigration of polysulfides to the lithium anode based on the intermediate position of the separator in the battery.…”

“…2,22 The polythionate arises from the reaction between thiosulfate and LiPSs. 2,14 Among them, the thiosulfate arises from the redox reaction between N-MoO 3 @Fe 2 (MoO 4 ) 3 and LiPSs. 2 These results indicate that N-MoO 3 @Fe 2 (MoO 4 ) 3 can anchor stray LiPSs in solution through chemical interaction.…”

“…The following power-law equation further proves the dynamic enhancement effect of the cells. 14,23 i = aυ b where i , υ , and a are the measured current, scanning rate, and constant coefficient, respectively. The b value is positively correlated with reaction rate.…”